There would no doubt be health benefits. But Ms. Stein is nevertheless spinning up a fairy tale — an appealing fairy tale to some, but still a fairy tale. To support the feasibility of her plan, Ms. Stein cited experts whose models in fact envision an energy transition taking decades longer than she posits. To support her health prognostication, she improbably cited Cuba’s experience losing access to Russian oil after the fall of the Soviet Union, after which, she pointed out, Cubans became healthier. In fact, they became healthier because they could no longer afford to smoke or drink alcohol and because so many involuntarily lost weight. “Cubans survived drinking sugared water, and eating anything they could get their hands on, including domestic pets and the animals in the Havana Zoo,” Richard Schiffman recounted in the Atlantic. “They became virtual vegans overnight.””

End all use of coal, oil, gasoline and nuclear power by 2030? That is one fantasy that not even Mr. Roarke could deliver.

“Don’t let Jill Stein on the island. Her fantasies are impossible even for us.”